1. Field of the Invention
The present invention generally relates to water supply systems and, more particularly, to pressure switch adaptors for such water supply systems.
2. Description of the Related Art
Pressure regulated water supply systems have developed over the years to include a water storage tank which provides an internal, flexible, pressurized air diaphragm. Typically, water is supplied from a well or other source to the tank by means of a pump. Thereafter, the water in the tank, which is pressurized to a predetermined degree by means of the air diaphragm, is distributed and used throughout the system as needed. When the pressure in the system falls as a result of water use, the pump is activated by a pressure-sensitive pump switch, introducing more water into the tank.
In systems of this type, the pressure switch which activates the pump is in communication with the water line leading from the pump to the tank. The pressure switch monitors the system water pressure and turns the pump on when the pressure falls below a predetermined lower level, thereby replenishing the water in the tank and restoring the system water pressure. The pressure switch deactivates the pump when the water pressure in the system has reached a predetermined upper level. Between the upper and lower pressure levels lies the operating range in which the pressurized tank supplies water to the system without activation of the pump.
Pressure switches of this type, although they work satisfactorily when new, tend to become encrusted with minerals or otherwise deteriorate due to their prolonged contact with water. This leads to a serious maintenance problem in existing systems, wherein the operation of the pressure switch is erratic and, eventually, the switch must be replaced. In an effort to solve the problems of encrustation resulting from switch exposure to water, systems have developed which place the pressure switch on the air side of the system rather than the water side.
U.S. Pat. No. 4,304,526, the disclosure of which is incorporated herein by reference, is exemplary of the foregoing systems wherein it discloses an improved well system and flow control tank which includes a pressure switch in communication with the interior of the tank's air diaphragm. The '526 patent has recognized the problems associated with encrustation of pressure gauges and pressure switches, and has attempted to solve those problems by providing a separate conventional diaphragm accessing port for the pressure switch. A separate pressurizing air valve, which has its own diaphragm accessing port, is provided to initially pressurize the diaphragm.
In the '526 patent, two ports are necessary to provide initial pressurization and pressure switch connections for the tank. Although this results in improved performance when compared to one port tanks which employ pressure switches on the water side of the system, it also leads to an increase in tank manufacturing costs over such one-port tanks. Also, by increasing the number of external ports, the likelihood that a tank leak will develop is correspondingly increased. Such an arrangement cannot be employed on existing one-port tanks due to the necessary addition of a separate port.
Therefore, there exists a need in the art for a combined pressure switch connection and pressurizing air valve which can be mounted to the tank via a single diaphragm accessing port. Furthermore, there exists a need in the art for such a combined pressure switch connection and pressurizing air valve which can be used to replace the pressurizing air valves and pressure switch connections in existing tanks to upgrade the overall system performance.